The present application generally relates to intervertebral implants, and more particularly, to an expandable intervertebral implant.
An intervertebral implant is inserted after removal of an intervertebral disk for stabilizing the intervertebral region until bone material which is filled in at the same time has grown to an osseous connection and strengthening.
An expandable intervertebral implant is known from U.S. Pat. No. 6,176,882 B1. The intervertebral implant comprises two spaced side walls, a front wall connecting the side walls at one end thereof, a back wall connecting the side walls at the other end, the walls defining a corresponding space within the walls, a bottom face, a top face, each face extending transversely to said walls, at least one engagement member disposed within the space defined by said walls, said engagement member having a surface oriented toward one of the bottom face or the top face, and two wedge members which are supported in the front wall and the back wall by a threaded spindle having two ends and two portions with opposite thread pitches, one end of the threaded spindle being rotationally supported in the front wall and the other end being rotationally supported in the back wall. The two wedge members are supported within the space in such a manner that, upon rotation of the threaded spindle in one direction, a distance between the wedge members decreases and, upon rotation of the threaded spindle in an opposite direction, the distance between the wedge members increases. The wedge members operate to move the engagement member reciprocally. The outer contour of the expandable intervertebral implant is rectangular. Therefore, the wedge members can be supported on one single threaded spindle.
Another expandable intervertebral implant is known, for example, from WO 2005/058209 A2. The implant includes a body having a longitudinal axis and including first and second axial walls spaced apart along a transverse axis, first and second transverse end walls extending between and interconnecting the first and second axial walls. The intervertebral implant includes an expansion member co-acting with the axial walls to expand the body along the transverse axis. The outer contour of the implant in a plane parallel to the end plates of the vertebral body is also rectangular. An intervertebral implant with a rectangular contour does not fit perfectly to the shape of the end plates of the vertebral body. For certain applications an anatomically-shaped intervertebral implant is desired.
US 2005/0125062 discloses a height adjustable intervertebral implant which has an anatomical shape.
Based on the above, there is a need to provide an expandable intervertebral implant which allows a facilitated insertion and at the same time has an improved simple handling of the expansion mechanism.